Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
hanh ca » hanh cac, hanh cat, hanh cua
va hanh » van hanh, va thanh, va danh
cac bac » cac bai, cac ban, cac cach
hieu va » lieu va, hieu qua
cac tac » cac toc, cac dac, cac tai
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
ca cua » co cua
cua te » cua tu

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach v nang ((le hoi) OR (ma hoa)). hieu va ((cac tac) OR (cac bac)) va hanh ca cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach v nang ((le hoi) or (ma hoa)). hieu va ((cac tac) OR (cac bac)) va hanh ca cua te~".
• Adding a wildcard symbol may retrieve word variants: tu sach v nang ((le hoi) or (ma hoa)). hieu va ((cac tac) OR (cac bac)) va hanh ca cua te*.